Ric Flair, a star of the professional wrestling world for decades, entered the hospital over the weekend facing "tough medical issues" that appear to have gotten even more serious. A World Wrestling Entertainment source told TMZ that Flair is now in a medically induced coma and will undergo a surgical procedure.

Exactly what caused Flair, 68, to go to the hospital in the first place is still not clear, but initially fans were told there was "no reason to panic." Early reports indicated it was for a "heart-related issue." Flair's manager sent a note to fans and friends:

That situation may have taken a turn for the worse, if news of the coma is correct. Details remain scarce, as fans await news of how Flair's surgery went.

Fellow wrestlers and industry veterans have been sending their thoughts to the "Nature Boy," a beloved legend of the squared circle: